If you don't mind asking him why the governor would need to be re-synchronized? Would the small difference in throttle shafts cause this problem? I've disassembled my carb. twice and have never had an idle issue or had to make any adjustments afterwards. Don't take my statement the wrong way as I'm not trying to say he's wrong but I'm just curious for an education sake.

When I post pictures some questions may get answered, but comparing the two throttle shafts closely, it looks like the position of the cable linkage hole is at a different angle when both are aligned to the full open position. So if I had to guess this is what is messing up the governor.